The Leader of Iran’s Islamic Revolution in a meeting with the high-ranking officials:

“Those that went back on their promises, feel they are at an impasse.”

Don’t you ever wait for the nuclear talks in your work plans. Ever. Do you own job. Look at the current situation in the country and make planning accordingly.
The talks could get somewhere…[they could reach] some positive points, half-positive points, negative [points]…whatever the result, do your own job. Don’t stop your work because of them. Fortunately, the esteemed foreign minister and officials in the negotiating delegation give accurate reports to the president, to the Supreme National Security Council. They are on top [of the issue]. They make decisions. They think. They study all aspects of the issue.
It’s also ok to critique. It’s ok to critique what these officials do. It’s ok to express one’s views.
However, first of all, be careful that these views and criticisms are not pessimistic. Those who are officials…I have of course made it clear during [the tenure of] all administrations that one should not view those who are on the field and are active at the forefront, pessimistically and with suspicion. Well, faithful, revolutionary, diligent and hard-working people are working on this [issue].
If there’s critique, it must be optimistic. It should not be pessimistic. Secondly, [criticism] should not undermine those who are making efforts and working on the field, nor should people be disappointed. I mean comments must not be made in such a way as to [disappoint people].
However, our negotiating team, thanks be to God, has resisted the bullying and excessive demands of the other side and will keep resisting under divine auspices [and] undoubtedly.
The one who reneged on its commitments is the other side. They themselves have now got bogged down in their reneging on their commitments. They have got stuck. I mean the party that went back on its promises and, in their own words, tore that contract, has now got mired down. They feel…they feel they are at an impasse more. They are feeling they are at a dead end.
We, thanks be to God, do not feel we are at an impasse. We managed to withstand hardships. We held out against many difficulties. We will withstand other hardships under divine auspices.

https://en.mfa.gov.ir/portal/playvideos/22301